Laying of yarns or filament by means of a high velocity feed means



2 Sheets-Sheet 1 mvsmoa: John J; lhc

Afforneys y 14, 1964 J. J..VINCENT LAYING OF YARNS 0R FILAMENT BY MEANS OF A HIGH VELOCITY FEED MEANS Filed Feb. 9, 1960 July 14, 1964 J. J. VINCENT. 3,140,633

LAYING OF YARNS OR FILAMENT BY MEANS OF A HIGH VELOCITY FEED MEANS 2 Sheets-Sheet 2 Filed Feb. 9. 1960 INVENTOR:

John J. Vim-am Afiorneys United States Patent 3,140,633 LAYING 0F YARNS 0R FILAMENT BY MEANS OF A HIGH VELOCITY FEED MEANS John Joseph Vincent, Aiderley Edge, England, assignor to The Manchester Coliege of Science and Technology, Manchester, England, a corporation of Great Britain Filed Feb. 9, 1960, Ser. No. 7,617 Claims priority, application Great Britain Feb. 14, 1959 12 Claims. (Cl. 83-402) This invention relates to the laying of yarns or filaments as, for example, in the operation of weaving a fabric.

Methods and apparatus hitherto known for such purpose include a shuttle or a mechanical weft layer arranged to carry an end or loop of yarn from a stationary package into a warp shed. A relatively new method has now been evolved in which the yarn is projected into the warp shed by a fluid jet of air or liquid, which latter method avoids the main disadvantage of inertia of the mechanical weft layer, but has its own disadvantages including limitation of the distance over which the yarn or filament can be so projected.

The present invention is based upon the appreciation of the possible use of momentum of the yarn or filament itself for its projection endwise as a means, for example, for laying the same into a warp shed and in spite of the non-rigid nature thereof.

To avoid ambiguity, it is hereby stated that the expression yarn will be used hereafter not only in it normal sense as defining a staple fibre yarn, but also to include a filament or group of filaments, and so as also to include other than textile yarns, for example, metal wires in the weaving of which a shuttle is normally employed.

The invention comprises the method of projecting a length of yarn endwise, for example, for laying it in a warp shed for the weaving of a fabric consisting in the step of imparting high endwise velocity thereto by momentary frictional contact with at least one moving surface so arranged as to project the yarn or filament in a predetermined direction by reason of the momentum thereby imparted to it.

The method aforesaid may include the further step of straightening the length of yarn as it is projected consisting in the application to the yarn initially at its leading end of the said frictional contact surface moving at a predetermined lineal velocity and consecutively applying rearwardly of such end means operating at a lineal speed which decreases progressively, whereby the momentum in the already projected portion of the yarn tensions the same and holds it relatively straight; and/ or the further step of arresting the yarn from its rear end when the required length has been projected, and severing the yarn length.

The invention also includes apparatus for carrying out the method aforesaid.

According to a preferred embodiment of the invention, apparatus for projecting a yarn endwise, for example, for laying it in a warp shed for the weaving of a fabric comprises a pair of driving wheels arranged to provide a nip between their peripheries, means for rotating said wheels at a speed to give them the required peripheral velocity at the nip and means for locating an end of yarn in the said nip in such manner that the yarn is projected from the nip with an endwise velocity.

The apparatus aforesaid may be characterised by means for retarding the rotation of the wheels progressively during projection of the yarn in such manner that the momentum in the projected length operates to hold it in tension and, therefore, relatively straight; and/ or further characterised by means for arresting movement of the "ice yarn after the required length has been projected and for holding the severed end of the said projected length.

The invention is particularly applicable in small-ware and broad looms to effect weft insertion into a warp shed from a stationary weft supply and may be used with textile yarns of natural or synthetic fibres or filaments of relatively non-rigid nature such as thin metal wire, all hereinafter generically termed yarn, and embodies the principle whereby endwise propulsion is obtained by effecting frictional contact of the yarn with one or more moving friction surfaces, such as the surface of a wheel or wheels or travelling band or bands, so arranged as to project the yarn endwise in the required direction.

When more than one friction surface is used, such as a pair of wheels to provide a nip, the distance apart is adjustable for different thicknesses of yarn, its compressibility and the compressibility of the friction surfaces themselves, surface spceds being the same at all points of contact.

The arrangement may be such that the surface speeds of point or line of friction contact may change while the yarn is being propelled, i.e. accelerated to produce yarn in excess of warp width for effect purposes; held constant for straight yarn on narrow fabrics; retarded to straighten and tauten the projected yarn.

Variation in speed may be obtained by connecting a constant speed shaft by a single Hookes joint or universal coupling through suitable gearing to the yarn feed such as a pair of wheels, so arranged that the desired retardation or acceleration period occurs during the period when the yarn is being fed. Variation in speed is also obtained from a four-bar kinematic chain or its derivatives, by elliptical gearing, by mechanical, electromagnetic, or fluid braking, or other known means.

The yarn may be stiffened by pre-treatment with an adhesive or by wetting and freezing before use.

In combination with the aforesaid arrangements and conditions taken separately or collectively, jets of gas or liquid may be provided in the direction of propulsion of the yarn to reduce air drag. Suction may be provided with or without the jets at the receiving side.

In combination with the aforesaid arrangements, taken collectively or separately, the yarn may be clamped on one or both sides of the delivery point while it is moving so as to arrest its movement and a weft feeler may be combined with a clamp.

After delivery of the weft, the position of the leading end may be adjusted by reversing the feed, or by a reverse feed on the supply side of the forward feed or by bending out of straight by mechanical means, such as a finger.

Novel effects may be achieved by inserting part picks or by inserting yarn as weft not at right-angles to the warp, using corresponding beat-up arrangement.

The projecting of the yarn may be initiated either by bringing forward its end into a friction nip, or by bringing friction surfaces into contact with yarn lying between them, or by deforming the friction surfaces, e.g. by inflation of tires on wheels, so as to reduce the gap between.

Weft may be inserted from both sides of a warp shed simultaneously or in any desired sequence.

The line of projection of the yarn may be raised or lowered relative to the level of the fell so that the warp threads may be shed at different levels and so that weft yarns may be projected into each of the sheds.

The yarn may be crimped, printed or otherwise treated while passing through the delivery system for its projections.

After the yarn has been projected into the shed, it may be tensioned before beating up or otherwise treated as may be desired.

In the accompanying drawings:

FIG. 1 is a diagram of one example;

FIG. 2 is a fragmentary drawing showing a modification of part of the apparatus of FIG. 1;

FIG. 3 is a view showing a pair of cones for attaining deceleration of the yarn drive during projection, and

FIG. 4 is a plan view of guiding means for the yarn for use with the arrangement of FIG. 3.

As shown in FIG. 1, the apparatus comprises a pair of wheels and 11 each fitted with a flat-tread resilient tire 10a and 11a respectively providing friction gripping surfaces for the yarn to be projected thereby. Diagrammatically, the wheels 10 and 11 are shown coupled by a crossed driving belt 12 whilst the wheel 11 is driven through a step-up gear train 13 for the required lineal speed. The input gear wheel of the gear train 13 is driven from a power drive such as an electric motor 14.

The wheel 10 is carried on a rocking arm 15 pivoted at 16 and carrying at its other end a gripping roller 17. Means for rocking the arm 15 comprises a cam 18, cam follower 19 and return spring 20. Means are provided for accurately limiting the separation of the rollers 10 and 11 during their operative cycle and is herein shown diagrammatically as a link 21, guide bracket 22 and adjustable stop nuts 23 on the link. Complementary with the roller 17 is a further gripping roller 24 which is adapted to be given controlled rotation as by means of a rack 25 and cam 26, the cams 10 and 26 being synchronized with the loom mechanism.

The warp shed is indicated diagrammatically by the line 27 and at the feed side is located severing means 28. Supplementary thereto, there may be a severing means 29 at the other side of the shed whilst a fan system is shown consisting of a blower 30, nozzles 31 on the feed side and a suction nozzle 32 at the other side. The severing devices are actuated by known mechanism synchronized with the movements of the loom.

As shown in FIG. 2, in place of the motor 14 there is provided a power drive 33 operating through gearing 34 and a floating shaft 35 of telescopic construction, the parts of which are adjustable rotationally and adapted to be locked in any set position by means of a screw 36. The shaft 35 has single I-Iookes couplings 37 and 38 respectively at each end. The final shaft 39 of the gearing 34 is timed with the loom cycle to give a whole number of revolutions relative to the revolutions of the loom crankshaft and the gearing 13 is equally arranged for the wheel 11 to have its revolutions a whole multiple of that of the shaft 39.

A yarn package 40 is shown with the yarn 41 located between the gripping rollers 17 and 24 and with its end just located in the normally open nip of the feed rollers 10 and 11.

In operation, timed with each opening of the warp shed of the loom, the cam 18 permits the spring 20 to rock the arm 15 bringing the wheel 10 into yarn-gripping proximity with the wheel 11 gripping the end of the yarn 41. The wheels 1t and 11 are maintained constantly rotating either at uniform speed by the motor 14 or with acceleration and deceleration as can be obtained in known manner by relative setting of the single Hookes joints 37 and 38 for difference of rotational angularity and for change of inclination of the shaft 35 by adjusting its telescopic length, the shaft 39 being slidable within its driving pinion.

The wheels lil and 11 are given a peripheral speed according to the distance to which the end is to be thrown. Thus, a peripheral speed of, say, 150 feet per second will throw the end of the yarn usefully some 60 inches before the action of gravity drops it, say, /2 inch assuming that such drop is permissible before it contacts the lower warp threads of the shed. Passage of the yarn end through the shed may be assisted by the provision of an air stream from the nozzles 31 which reduces the air resistance and the yarn end may be caught by the suction nozzle 32. Before the severing means 28 and 29 are brought into operation, the cam 18 brings the gripping roller 17 into engagement with the yarn between it and the roller 24, which arrests the yarn and allows it to straighten in the warp shed by reason of its momentum. Then, the cam 26 is actuated to impart a counter-clockwise rotation to the wheels 24 thereby ensuring straightening of the yarn. The severing means 28 is then actuated and the cam 26 effects further withdrawal of the yarn until the newly severed end is positioned in the open nip of the rollers 10 and 11 ready for the next pick.

Resistance to movement of the end of the yarn is essentially air resistance and, therefore, such resistance is proportional to the square of the velocity. In order that momentum of the yarn may be used to keep it in tension as it is entering the shed, the feed wheels 10 and 11 may be given a decelerating rotation partially or completely to compensate for the retardation caused by the air resistance. Thus, if the retardation of the wheel is equal to or greater than that caused by the air, then the yarn will remain taut during projection, but useful retardation can be less. Such retardation is obtainable through the action of the Hookes joints and by selecting the gearing ratios so that, during the throwing of the yarn, a useful part of the retardation period may be employed at the right time.

In a modification as shown in FIG. 3, in order to obtain deceleration of the yarn drive during projection, a pair of conical rollers 50, 46a and 41a are used, arranged with their axes N and M inclined to each other and in the same plane in the manner of bevel gearing, to provide a nip for the yarn 41 in such plane, the lineal speed of the surfaces at the nip decreasing towards the smaller radii. The thread 41 is guided by means of a guide tube 53 oscillated by means of an arm 54, cam 55 and return spring 56. The outlet end of the tube 53 is arranged to move in the plane of the nip of the rollers for moving such eye along the nip synchronized to move the yarn outwards towards the smaller radii at a rate of movement necessary to provide the required deceleration, and then returned to a normal position for starting the next yarn projection.

I claim:

1. An apparatus for laying a length of yarn as a weft yarn in a shed of warp threads including feed rollers for a length of the yarn; means for driving the rollers including at least one single Hookes joint and a step up gear train so arranged as to provide a cycle of acceleration and deceleration and having a part of its deceleration cycle suitable for progressively decreasing the velocity of projection, and means for engaging the yarn with such rollers, said means being timed so as to use such portion of the cycle, whereby the projected portion of yarn is maintained in tension and relatively straight by virtue of its mo mentum.

2. An apparatus for projecting a length of yarn end-' wise to lay it in the warp shed for the weaving of a fabric, comprising means in the form of at least one moving surface for imparting high endwise velocity to the yarn to project it in a predetermined direction by reason of the momentum thereby imparted to it, means for arresting the projected yarn from its rear end when the required length has been projected, means for moving the yarn-arresting means so as to partially retract the yarn after laying, and means for severing the yarn length.

3. Apparatus according to claim 2 further characterised in that the means for projecting the yarn comprises a pair of conical rollers arranged with their axes inclined and in the same plane so as to provide a longitudinal nip and means for guiding the yarn along said nip.

4. The method of laying a length of yarn in a predetermined position, for example, as a weft yarn in the shed of warp threads in a loom, consisting in the steps of imparting a high endwise velocity to the yarn from its leading end and rearwards along its length by momentary frictional contact with at least one moving surface so arranged as to project the yarn in free flight in air in a predetermined direction by reason of the momentum imparted to it, and checking the lineal movement of the projected yarn by its rear end to determine its projected length, the velocity of projection being of the order of 150 feet per second and such that the yarn length is fully extended before it loses free suspension and makes contact with any surface such as that of the Warp threads and moving the yarn-checking means to partially retract the yarn after laying.

5. The method of projecting a length of yarn endwise, as by laying it in a Warp shed for the weaving of a fabric, consisting in imparting high endwise velocity thereto by by momentary frictional contact with at least one moving surface so arranged as to project the yarn in a predetermined direction by reason of the momentum thereby imparted to it and straightening the yarn as it is projected by applying to the yarn, initially at its leading end, the friction contact surface moving at a predetermined lineal velocity and consecutively applying rearwardly to such end means operating at a lineal speed decreasing progressively, whereby the momentum in the already-projected portion of the yarn tensions the same and holds it relatively straight, and severing the yarn length.

6. The method of projecting a length of yarn endwise, consisting in imparting high velocity thereto of the order of 150 feet per second by momentary frictional contact commencing with each length from its leading end with two moving surfaces moving at the same speed at the instant of contact of the same with the yarn and so arranged as to project the yarn in a predetermined direction by reason of the momentum thereby imparted to it, and arresting the projected yarn from its rear end when the required length has been projected, and severing the yarn length.

7. The method of laying a length of yarn in a predetermined position, for example, as a weft yarn in the shed of warp threads in a loom, consisting in the steps of imparting a high endwise velocity of the order of 150 feet per second to the yarn from its leading end and rearwards along its length by momentary frictional contact with at least one moving surface so arranged as to project the yarn in free flight in air in a predetermined direction by reason of the momentum imparted to it, and checking the lineal movement of the projected yarn by its rear end to determine its projected length, the velocity of projection being such that the yarn length is fully extended before it loses free suspension and makes contact with any surface such as that of the warp threads, and including the further step of retracting the projected yarn by its rear end after laying so as to straighten the same.

8. The method of projecting a length of yarn endwise, for laying it, for example, in a warp shed for the weaving of a fabric, consisting in the step of imparting an endwise velocity thereto by momentary frictional contact with and between at least one moving and one complementary moving surface so arranged as to form a nip to project the yarn endwise in a predetermined direction by reason of the momentum thereby imparted to it, the said endwise velocity being at least such that the yarn will be carried by its momentum for the required distance before contact with any adjacent surface, the step of arresting the projected yarn from its rear end when said length has been projected, and the further step of progressively reducing the effective velocity of the moving frictional surfaces in contact with the yarn during its projection so as at least be not greater than the residual velocity at any moment of the already projected part of the yarn.

9. An apparatus for projecting a length of yarn end wise, for laying it, for example, in a warp shed for the Weaving of a fabric, comprising at least two members having complementary movable surfaces so arranged as to provide a nip for the yarn, means for driving at least one of said moving surfaces so as to project the yarn endwise in a predetermined direction by reason of the momentum thereby imparted to it, an endwise velocity of the order of feet per second being imparted commencing at the leading end for each length of yarn and such that the yarn will be carried by such momentum for the required distance before making contact with any adjacent surface, and means for arresting the projected yarn from its rear end when the said length has been projected.

10. The continuous method of projecting a length of yarn endwise, as by laying it in a warp shed for the weaving of a fabric, consisting in applying high endwise velocity thereto by momentary frictional contact with at least one moving surface so arranged as to project the yarn in a predetermined direction by reason of the momentum thereby imparted to it and straightening the yarn as it is projected, by applying to the yarn, initially at its leading end, the friction contact surface moving at a predetermined lineal velocity, and consecutively applying rear- Wardly to such end means operating at a lineal speed decreasing progressively, whereby momentum in the already projected portion of the yarn tensions the same and holds it relatively straight, severing the yarn length, and retracting the yarn so that the newly severed end is brought into the region of the friction contact surface for the projection of the next length of yarn.

11. An apparatus for projecting a length of yarn endwise, comprising two moving surfaces providing a nip between them with which the yarn frictionally contacts and which imparts high velocity to the yarn and projects it in a predetermined direction, means providing an air stream in the direction of propulsion of the yarn, means for severing a length from the yarn, and means for retracting the yarn back to the nip after the severance of a length therefrom so that the newly severed end is brought into the region of the said moving surface for the projection of the next length of yarn.

12. An apparatus for projecting a yarn for laying it, for example, in the warp shed for the weaving of a fabric, comprising, a pair of driving Wheel arranged to provide a nip for the yarn between their peripheries, means for rotating the wheels at an equal speed to give them a peripheral velocity at the nip equal to the required endwise velocity of the yarn, and means for retarding the rotation of the wheels progressively during projection of the yarn in such a manner that the momentum in the projected yarn length operates to hold it under tension and therefore relatively straight during projection.

References Cited in the file of this patent UNITED STATES PATENTS 

1. AN APPARATUS FOR LAYING A LENGTH OF YARN AS A WEFT YARN IN A SHED OF WRAP THREADS INCLUDING FEED ROLLERS FOR A LENGTH OF THE YARN; MEANS FOR DRIVING THE ROLLERS INCLUDING AT LEAST ONE SINGLE HOOKE''S JOINT AND A STEP UP GEAR TRAIN SO ARRANGED AS TO PROVIDE A CYCLE OF ACCELERATION AND DECELERATION AND HAVING A PART OF ITS DECELERATION CYCLE SUITABLE FOR PROGRESSIVELY DECREASING THE VELOCITY OF PROJECTION, AND MEANS FOR ENGAGING THE YARN WITH SUCH ROLLERS, SAID MEANS BEING TIMED SO AS TO USE SUCH PORTION OF THE CYCLE, WHEREBY THE PROJECTED PORTION OF YARN IS MAINTAINED IN TENSION AND RELATIVELY STRAIGHT BY VIRTUE OF ITS MOMENTUM. 